private void Quant(ref IPhrase aPhr)
{
// look for quantifier here
if (lex != null && (lex.Text == "{" ||
lex.Text == "*" ||
lex.Text == "+" ||
lex.Text == "?"))
{
ExprInt lMin = null, lMax = null;
//{1..5}
if (lex.Text == "{")
{
lex = lex.Next();
lMin = ParseIntValue();
if (lex.Text == ".")
{
lex = lex.Next();
ExpectSign(".");
if (lex.Text == "*")
{
lMax = new ExprInt(Int32.MaxValue);
}
else
{
lMax = ParseIntValue();
}
}
else
{
lMax = lMin;
}
ExpectSign("}");
}
else if (lex.Text == "*")
{
lMin = new ExprInt(0);
lMax = new ExprInt(int.MaxValue);
lex = lex.Next();
}
else if (lex.Text == "+")
{
lMin = new ExprInt(1);
lMax = new ExprInt(int.MaxValue);
lex = lex.Next();
}
else if (lex.Text == "?")
{
lMin = new ExprInt(0);
lMax = new ExprInt(1);
lex = lex.Next();
}
else
{
throw new GrammarSyntaxException("Недолжно быть. Неподдерживаемый знак после нетерминала " + lex.Text);
}
QuantifiedPhrase lQuant = new QuantifiedPhrase(mGrammar, aPhr, lMin, lMax);
aPhr = lQuant;
}
}
//Seq := T | NT | "(",Phrase,")"
private IPhrase Seq()
{
if (lex == null)
{
throw new GrammarSyntaxException("unexpected end of rule");
}
IPhrase lPhr;
if (lex.Type == LexemType.LeftBr)
{
lex = lex.Next();
lPhr = ParsePhrase();
Expect(LexemType.RightBr, ")");
Quant(ref lPhr);
}
else if (lex.Type == LexemType.Sign && lex.Text == "[")
{
lex = lex.Next();
lPhr = new QuantifiedPhrase(mGrammar, ParsePhrase(), 0, 1);
ExpectSign("]");
}
else if (lex.Type == LexemType.Sign && lex.Text == "{")
{
lex = lex.Next();
lPhr = new QuantifiedPhrase(mGrammar, ParsePhrase());
ExpectSign("}");
}
else if (lex.Type == LexemType.Sign && lex.Text == "<")
{
lex = lex.Next();
if (lex.Type != LexemType.NotTerminal)
{
throw new GrammarSyntaxException("Name expected");
}
string lName = lex.Text;
lex = lex.Next();
ExpectSign(">");
lPhr = PlaceHolderAssign(lName);
Quant(ref lPhr);
}
else if (lex.Text == "#")
{
lex = lex.Next();
lPhr = Expr();
}
else
{
//терминальный или не терминальный
if (lex.Type == LexemType.Terminal)
{
lPhr = new Terminal(mGrammar, lex.Text);
lex = lex.Next();
}
else if (lex.Type == LexemType.NotTerminal)
{
lPhr = TransCall();
}
else
{
throw new GrammarSyntaxException("Terminal or Non-Terminal symbol expected");
}
Quant(ref lPhr);
}
return(lPhr);
}
